Testing the fertility of the spermatozoa

: The sperm count, an absolutely necessary examination, seems no longer sufficient to establish a prognosis of fertility. Fertilization in vitro, for a diagnostic purpose, would be the ideal examination, but because of the ethical and technical problems it raises, other tests have been developed. The test of spermatozoid survival at 24 hours in Menezzo's B2 medium and interspecific fertilization in vitro (hamster-test) are carried out on isolated spermatozoids according the FIV protocol. The survival test provides two parameters: the presence of mobility and the rate of retention of the mobility after 24 hours. With the hamster-test it is possible to study the penetration and decondensation of the spermatozoids in the ovocytes. The results obtained with the survival test show that the absence of gradual mobility and a retention rate below 25 p. cent after 24 hours, significantly affect the cleavage of ovocytes during FIV. These two parameters affect, in a similar fashion, the percentage of fertilized ovocytes in the hamster-test. The latter seems less specific than the survival test to establish a prognosis before FIV. However, it is interesting as it allows the study of the different stages of fertilization of spermatozoid samples, from the same ejaculation, under varied experimental conditions. These tests require a standardization and present a definite advantage during exploration prior to FIV, AIC.